*Current version: 2.0.0 Last updated: 3/5/2024
- Visit https://owshiny.epa.gov/survey-design-tool to launch the tool from EPA's Office of Water Shiny server. If using a large sample frame or if your design uses >2GB of memory, consider running the tool locally from your own workstation for faster processing.
- To launch the tool locally, click the green 'Code' button and download the zip file which contains the code repository. Open the app.R file in RStudio for local app deployment. RStudio will recognize the Shiny script and provide a Run App button at the top of the editor pane (look for the green play triangle).
- Note: Requires the R package spsurvey Version ≥5.1.0.
This Shiny app presents an easy-to-use user interface for the calculation of spatially balanced survey designs of point, linear, or areal resources (i.e. lakes, streams, wetlands and coastal resources) using the Generalized Random-Tessellation Stratified (GRTS) algorithm (Stevens and Olsen 2004). The tool utilizes functions found within the R package, spsurvey: Spatial Sampling Design and Analysis and contains many sampling design features including stratification, unequal and proportional inclusion probabilities, replacement (oversample) sites, and legacy (historical) sites.
The output of the Survey Design Tool contains sampling locations which are designed and balanced by user specified inputs and allows the user to export these locations as a point shapefile or a flat file. The output provides design weights which can be used in categorical and continuous variable analyses (i.e., population estimates). The tool also gives the user the ability to adjust initial survey design weights when implementation results in the use of replacement sites or when it is desired to have the final weights sum to a known frame size.
- For further survey design discussion and use cases, review the spsurvey vignette for Spatially Balanced Sampling and EPAs National Aquatic Resource Surveys (NARS) which are designed to assess the quality of the nation's rivers and streams, lakes and reservoirs, wetlands, and coastal waters using GRTS survey designs.
- For Survey Design Tool questions, bugs, feedback, or tool modification suggestions, please contact Garrett Stillings at: [email protected].
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